Orbital Eying ATK Solid Propulsion System for Antares First Stage

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Amy Svitak

Wed, 2014-04-30 12:40

A proposed merger between Orbital Sciences Corp. and the aerospace and defense divisions of ATK could yield a more powerful -- and politically palatable – Antares launch vehicle, according to company officials.

Orbital Chairman and CEO David Thompson says his company is considering an ATK proposal to develop a solid-rocket propulsion system to replace the modified Russian NK-33 engines that power the Antares rocket's Ukrainian-built first stage.

In an April 29 interview following the proposed merger announcement, Thompson said ATK's bid is one of three – including two offered by Russian suppliers – that Orbital is currently reviewing.

“ATK has made that proposal and it's attractive,” Thompson said. “We haven't made any final decisions on which way to go there, but with the recent geopolitical events and the progress ATK has made over the last few years in advancing large composite-case solid rocket motors, that alternative is looking more and more attractive.”

The proposed merger, which is expected to close this year, would see Dulles, Va.-based Orbital bring ATK's space propulsion work in house, increasing Orbital's control over its rocket manufacturing from 40-45% today to 80% under the combined entity.

ATK, which built the Space Shuttle Reusable Solid Rocket Motors, is developing much of the core-stage boost for NASA's new Space Launch System. The company also produces the Antares launcher's Castor-30B solid-rocket upper stage, as well as an optional Star 48BV solid-fueled third stage.

In addition to creating a more vertical manufacturing operation, choosing a U.S.-sourced booster could help Orbital avoid scrutiny from U.S. national security hawks eager to end America's reliance on Russian rocket technology.

A large solid rocket first stage would also boost Antares' current 5,000-kg lift capacity to low Earth orbit by “20-25%, depending on the orbit in question,” Thompson says.

The increase would give Antares a lift capacity comparable to the SpaceX Falcon 9 v1.1 for launching small payloads to geosynchronous orbit, and could potentially broaden Orbital's customer base beyond its $1.9-billion International Space Station cargo resupply contract with NASA to include the U.S. Defense Department.

“We've submitted to the Air Force our intention to on-ramp Antares in some configuration to its Evolved Expendable Launch Vehicle (EELV) program in the future,” Thompson said. “That is our aim over the next couple of years.”

Thompson said the company needs three years to develop a new Antares first stage, though a demonstration flight for the rocket might not be necessary.

“There may be ways in which the results of that sort of demonstration could be achieved short of a full-up demonstration, and that's one of the factors we still have to work our way through,” he said.